/*CODED BY mahmudulsakib2019
  DATE:-27/3/2024;TIME:-17:00 PM
  BANGALDESH , SYLHET*/
#include<bits/stdc++.h>  
using namespace std;
typedef unsigned long long  ll;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int t;
    cin >> t;
    while(t--) {
      ll a,b=20,c,count;
      cin >> a;
      bool start=false;
      vector<ll>p(a);
      vector<ll>q,s;
      for(ll i=0;i<a;i++){
        cin >> p[i];
      }
      for(ll i=0;i<a;i++){
        if(p[i]==1){
          start = true;
          b=min(b,i);
        }
        else if(p[i]==2){
          b=20;
          start = false;
        }
        else if(p[i]==3){
          if(start){
            c=i;
            count = (c-b)+1;
            q.push_back(count);
          }

        }
      }
    if (!q.empty()) {
        auto it = max_element(q.begin(), q.end());
        cout << *it << endl;
    }
    }
    return 0;
}